Fuel oil compositions of improved combustion characteristics



April 16, 1963 R. GAY ETAL 3,085,866

FUEL on. COMPOSITIONS OF IMPROVED COMBUSTION CHARACTERISTICS Filed Feb. 19, 1959 5'0 5'\ HORSEPOWER OUTPUT to q- I0 (\I XBGNIEDIOWS Raymond Guy t Emmunue| Sigunos nven ors By 2 Attorney States atent 3,085,866 Patented Apr. 16, 1963 fire The present invention relates to fuel oil Compositions and more particularly to fuel oil compositions with improved combustion characteristics.

The term fuel oil, as used in the present invention is taken to mean all liquid hydrocarbons, for example, gas oil, distillate oil, used as fuels for burners and furnaces or as fuels for diesel engines.

It is often necessary to improve the properties of fuel oils, particularly the combustion properties of the oils. Thus, it has been found, especially in diesel engines, that when the quantity of fuel injected is increased, to raise the power of the engine, there is a copious liberation of smoke in the exhaust gases. This phenomenon is due to the incomplete combustion of the fuel when a certain quantity of injected fuel is increased. The result of this is that the increase in power output obtained is far from proportional to that of the fuel injected, hence the higher specific combustion. In addition, this increased consumption leads to the formation of deposits in the combustion chambers and on the pistons and thus to a decrease in the performance and efliciency of the engine.

The applicants have discovered that it is possible to improve the properties of the fuel oil, particularly with regard to its combustion characteristics, by adding a small proportion of two or more sulphonates of different metals, to the oil.

The present invention consists of a composition comprising a fuel oil and a small proportion of two or more sulphonates of the metals of groups II, IV, V, VIb or VIII of the periodic table. The mixture used according to the invention may comprise sulphonates of several metals of the same group. Particularly good results are obtained when a mixture of the sulphonates of tin and lead is used.

The metal sulphonates used in the present invention are preferably the metal salts of acids obtained by sulphonating white oils, oily fractions or synthetic alkyl aromatic compounds. These sulphonic acids have a molecular weight above 400 and the metal sulphonates derived from these acids are readily soluble in oil and particularly insoluble in water.

In accordance with the present invention the quantity of each of the sulphonates added to the fuel oil is preferably within the range of from 0.05 to l, and more particularly 0.1 to 0.5 mg. atom of metal per kilogram of fuel oil.

In a preferred embodiment of the present invention, a mixture of the metallic sulphonates is prepared and this mixture is added to the fuel oil. In a further preferred embodiment of the invention, the mixture of two sulphonates comprises from 80 to 20% of the one sulphonate and from 20 to 80% of the other sulphonate.

The following examples illustrate the efficacy of the mixture of the sulphonates of the present invention, particularly with regard to the reduction in smoke index.

Example I Tests were carried out on a General Motors diesel engine (GJM. 371) having the following characteristics:

Number of cylinders 3.

Bore 108 mm. (4%"). Stroke 127 mm. (5"). Cylinder capacity 3437 mm. (212 cu. in.). Temperature of water 80 C.

Temperature of oil 107 C.

Speed 1200 rpm.

The measurements of the exhaust smoke were conducted with the smoke indicator known as the Von Brand Smokemeter. Using this apparatus it is possible to measure the smoke contained. in the exhaust gas by passing the latter through a constantly unwinding paper screen. The intensity of the spot obtained is measured by interpolation between twostandards (one white, the other black) and this determination is carried out either by comparison with a datum scale or more accurately, by measuring the percentage of light reflected by means of a photo-reflectometer.

The diesel engine was operated at a determined output, fed with a gas oil alone or with a gas oil plus an additive and the following characteristics were measured:

The gas oil used has the following characteristics:

Density at 15 C. gm./cc. 0.857 Engler viscosity at 20 C. 1.43 Sulphur content 1% The results of the tests are summarised in the following table:

Cetane number Gas oil plus Gas oil Gas oil mixture of Tin plus Tin plus Lead and Lead Charac- Sulphonato Sulphonate Sulphonate Output terlstics Gas Oil (0.5 mg. (0.5 mg. (0.25 mg. atom in H.P. Measured Alone atom Su atom Pb Sn per kg. of

per kg. per kg. gas oil and 0.25 gas oil) of gas oil) mg. atom of Pb per kg. of gas oil) 42 I 8. 5 2. 5 1. O 10.14 10.09 10. 04 10.03 T 242 237 237 238 Ca 207. 9 205. 2 205. 6 205. 5 45 I 3. 5

C 10. 82 10.69 T 258 245 CH 206.7 204. 2 48 I 4 3 C 11. 52 11. 30 T 237 269 Ca 206. 2 202.3 51 I 4. 5 3. 5 G 12. 24 11. 86 T 288 285 C, 208 201. 6 54 I 5 4 O 12. 7 12. 44 T 296 291 C. 201.9 197.8 55.8""--. I 5. 5 4. 5 C 13.13 12.92 T 307 303 O. 202. 2 199 The accompanying drawing represents graphically the relationship between the smoke index (ordinate) and the output in horsepower (abscissa), thus Curve 1: Engine supplied with gas oil alone.

Curve 2: Engine supplied with gas oil plus tin sulphonate.

Curve 3: Engine supplied with gas oil plus lead sulphonate.

Curve 4: Engine supplied with gas oil plus mixture of tin and lead sulphonates.

From these graphs it can be seen that for a given smoke threshold (e.g. smoke index 3.5) there is a gain in horse power of from 45 to 54, that is a gain in power of some 20% when a mixture of tin and lead sulphonate according to the present invention is used whilst when lead or tin sulphonate are used alone the gain in power is considerably less, that is, from 45 to 51 HP.

Example II Speed 1500 r.p.m. Petroleum inlet temperature 78 01-? C. Petroleum outlet temperature 85 C.i1 C. Temperature of crank case oil 55 C.:l C. Injection advance 21.

Time of test 120hours.

and the results obtained are as shown in the following table:

Gas 011 plus mixture of Tin Gas oil plus and Lead Sul- Lead Sulphophonate (0.25 Gas oil nate (0.5 mg. mg. atom Pb alone atom Pb per per kg. 01 gas kg. of gas oil) oil and 0.25

mg. atom S per kg. of gas oil) Scratching of Crown 7. 4 3. 6 2. 6 Inside of piston 22. 5 15.0 7. 5 52. 1 27. 5 23. 7 Skirt before washing 1. 97 4. 3 O. 9 Sln'rt after washing 025 0. 7 Sludge: general parts 41. 23.0 29. 6

When the mixture of tin and lead sulphonates was added to the gas oil it was noticed that there was a de crease in exhaust smoke and the engine was much cleaner, particularly the injection system and especially the in jection needle.

What we claim is:

1. An improved liquid hydrocarbon fuel oil composition which normally has a strong tendency to give exhaust smoke in a diesel engine to which has been added a smoke reducing mixture of from 20 to by weight of an oil soluble lead sulphonate and from 20 to 80% by Weight of an oil soluble tin sulphonate, both of said sulfonates being derived from sulfonic acids having a molecular weight in excess of 400 and said mixture being present in an amount of from 0.05 to 1 milligramatom of metal per kilogram of said fuel.

2. An improved fuel oil composition as defined by claim 1 wherein said fuel oil is a diesel fuel.

3. An improved fuel oil composition as defined by claim 1 wherein said mixture is present in an amount of from 0.1 to 0.5 milligram-atom of metal per kilogram of said fuel.

4. An improved fuel oil composition which comprises a petroleum gas oil to which has been added a mixture of about 50% by weight of an oil soluble lead sulphonate and about 50% by weight of an oil soluble tin sulphonate, each of said sulfonates being derived from a sulfonic acid having a molecular weight in excess of 400, said mixture being present in an amount to give about 0.5 milligram-atom of metal per kilogram of said gas oil.

5. A fuel oil composition as defined by claim 1 wherein the sulfonate radical is derived from sulfonic acids obtained by sulfonating white oils.

6. A fuel oil composition as defined by claim 1 wherein the sulfonate radical is derived from sulfonic acids obtained by sulfonating oily fractions.

7. A fuel oil composition as defined by claim 1 wherein the sulfonate radical is derived from sulfonic acids obtained by sulfonating synthetic alkyl aromatic compounds.

References Cited in the file of this patent UNITED STATES PATENTS 2,141,848 Adams et a1 Dec. 27, 1938 2,151,432 Lyons et al Mar. 21, 1939 2,258,297 Miller et a1. Oct. 7, 1941 2,296,069 Talbert et a1. Sept. 15, 1942 2,560,542 Bartleson et al. July 17, 1951 2,591,503 Bottoms Apr. 1, 1952 2,789,892 Pinotti Apr. 23, 1957 FOREIGN PATENTS 776,189 Great Britain June 5, 1957 

1. AN IMPROVED LIQUID HYDROCARBON FUEL OIL COMPOSITION WHICH NORMALLY HAS A STRONG TENDENCY TO GIVE EXHAUST SMOKE IN A DIESEL ENGINE TO WHICH HAS BEEN ADDED A SMOKE REDUCING MIXTURE OF FROM 20 TO 80% BY WEIGHT OF AN OIL SOLUBLE LEAD SULPHONATE AND FROM 20 TO 80% BY WEIGHT OF AN OIL SOLUBLE TIN SULPHONATE, BOTH OF SAID SULFONATES BEING DERIVED FROM SULFONIC ACIDS HAVING A MOLECULAR WEIGHT IN EXCESS OF 400 AND SAID MIXTURE BE- 